Lift hook with self-operating safety latch



Sept. 25, 1962 s.- P. LUNDSKOG LIFT HOOK WITH SELF-OPERATING SAFETY LATCH Filed Feb. 24, 1960 2 Sheets-Sheet 1 P 2 INVENTOR.

574W P. ZZ/IVDSA/06;

Sept. 25, 1962 s. P. LUNDSKOG LIFT HOOK WITH SELF-OPERATING SAFETY LATCH 2 Sheets-Sheet 2 Filed Feb. 24, 1960 INVENTOR.

ACZ'ORNEY 3,055,696 LIFT HOGK WITH SELF-OPERATING SAFETY LATCH ten I. Lnndskog, (Ietlar Creek Township, Ind, assignor to United States Steel Corporation, a corporation of New Hersey Feb. 24, 1960, Ser. No. 10,589 3 Claims. (Cl. 294-83) The present invention relates generally to lift hooks and more particularly has as its primary object to provide a self-operating lift hook and safety latch assembly.

This and other objects will become more apparent after referring to the following specification and attached drawings, in which:

FIGURE 1 is a front elevational View;

FIGURE 2 is a side elevational view partly in section;

FIGURE 3 is a substantially diagrammatic View showing the lift hook of the invention in position preparatory to engaging a load in the form of a bail;

FIGURE 4 is a view similar to FIGURE 3 showing the hook in an advanced position preparatory to engaging the load;

FIGURE 5 is a view similar to FIGURE 3 showing the hook in lifting engagement with a load;

FIGURE 6 is a view similar to FIGURE 3 showing the hook being released from engagement with the load; and

FIGURE 7 is an end view of FIGURE 6.

Referring more particularly to the drawing, reference numeral 2 designates generally the assembly of my invention which includes a lift hook 4 having a shank 6, load-supporting or saddle portion 8, and a bill Ill. The shank 6 is formed with a shoulder 12 adjacent its lower end for seating a collar 14. Collar 14- is provided with trunnions 16 projecting from opposite sides thereof for a purpose which will become apparent. A projection 1% extends from the hook t immediately below the shoulder 12 and above the bill 10, as best shown in FIGURE 1. Projection 18 provides a cam surface which is used in the unlatching operation as will be explained more fully hereinafter. A projection 20 depends from the bottom of the saddle portion 8.

A pair of hook-shape plates 22 connected together in spaced relation at their lower ends by a shaft 24 is pivotally mounted on the trunnions 16 of the collar 14 in opposed relation to the lift hook straddling the bill 10. A projection 26 depends from the lower portions of each of the plates 22 which corresponds with the projection 20 on the bottom of the lift hook. The projection 20 and the projections 26 provide opposed cam surfaces which define a V notch 28 therebetween when the assembly is in normal closed position, as best shown in FIGURE 1.

In operation, to engage a lift plate P of a carrier bail (not shown) or other lift apparatus that presents an aperture or slot in which the hook may engage, the hook and latch assembly of the invention is lowered onto the top of the lift plate, and as the assembly is lowered it is centered on the edge of the lift plate by means of the projections 20 and 26 so that the lift plate edge enters the V notch 28, as shown in FIGURE 3. As the assembly is lowered further the lift hook and the latch formed by the pair of pivoted hook-shape plates spread apart in 3,055,696 Patented Sept. 25, 1962 the position shown in FIGURE 4. Further lowering results in the hook and latch entering the aperture of the lift plate. After the aperture of the lift plate has thus been engaged the hook and latch drop by gravity so that the hook is latched and ready to lift the lift plate, as best shown in FIGURE 5. The projections 20 and 26 provide the weight needed to insure that the hook and latch will assume and remain in closed position when suspended, as shown in FIGURES 3 and 5.

To disengage the hook after the lift plate and carrier have been lowered to the floor, the hook is lowered until the top edge of the lift plate strikes the throats of the hook and latch and then follows the cam surface provided by the projection 18 to spread the hook and latch to open position, as shown in FIGURE 6. The hook and latch assembly is then moved along the edge of the lift plate away from the aperture of the lift plate to the position shown by broken lines in FIGURE 7 so that the assembly can be raised free of the lift plate.

Thus, the hook and latch assembly provides an arrangement whereby the hook is automatically closed when in lifting position so that a load cannot escape from the hook. Further, the unique structure of the hook and latch assembly renders it self-openable so that it is not necessary to employ a floorman for manipulating the hook to engage or disengage from a load. The hook and latch assembly of the invention can be manipulated to en gage and disengage by the crane operator alone.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A self-operating lift hook and safety latch assembly comprising a lift hook, a pair of hook-shaped plates pivoted to said lift hook in opposed relation thereto, and opposed cam surfaces on said lift hook and on said pair of plates defining a V notch therebetween.

2. A self-operating lift hook and safety latch assembly comprising a lift hook having a shank, a load-support portion and a bill, a pair of hook-shaped plates pivoted to the shank of said lift hook in opposed relation to said lift hook, the bill of said hook being normally received between said hook-shaped plates, and opposed cam surfaces on the lower portions of said lift hook and said pair of plates normally defining a V notch therebetween.

3. A self-operating lift hook and safety latch assembly as defined by claim 2 including a cam surface on said lift hook adjacent the pivot point of said plates, said lastnamed cam surface projecting between said plates.

References Cited in the file of this patent UNITED STATES PATENTS 1,860,121 Trout May 24, 1932 2,426,099 Hershowitz Aug. 19, 1947 2,476,734 Jellison July 19, 1949 2,645,834 Morehouse July 21, 1953 2,958,557 Cianchette Nov. 1, 1960 FOREIGN PATENTS 63,768 France Apr. 27, 1955 

